Breaking the Physics Engine Collision

Help and Feedback Creations Feedback
1

I don’t have posting access to the engine bug reports forum at this time, so I thought I’d at least get this out in the open.

I’ve created a simple ‘particle chamber’ of fast bouncing glowing light particles. You can visit the place here. Basically I’ve built the chamber and it’s supposed to contain the particles, yet they escape. Each particle has a body force to give it ‘zero gravity’ and is initialized with some velocity. The chamber is an inverted cylinder mesh (collision set to default) with a top and bottom cap. I don’t understand why it won’t provide sufficient collision boxes.
robloxapp-20221126-2028289.wmv (669.5 KB)

2

Most collision checking methods, probably including the one used by Roblox when set to default, don’t work very well with concave objects, they usually have optimizations in them that only work for convex ones. Also separately your particles and cylinder are probably too small for the size of the physics step, so they are phasing through.

1 Like
3

Thanks for the heads up. Do I have any options to besides slowing down the particles and making the chamber bigger?

4

A classic solution would be to fake the effect using an animation.

1 Like
5

Actually, if you want to preserve the “realness” of the effect and not just make it a baked animation, you could hide a scaled up model of this device out of sight, then copy and scale down the positions for the small version so it looks the same.

6

Thank you! Those are good options.

1 Like
7

For best collision, make the collision fidelity precise, not default:
image

You could use Roblox’s particle system & make the brightness high enough to get that neon effect. Use TweenService is some capacity, or, make your own 2D or 3D particle system, for 3D anchor the parts/mesh parts and use equations online.

1 Like